Graffiti Sketch Awesome AI Builder With Original Signature

Graffiti quick sketch style, exaggerated stylized depiction of a capable awesome AI builder character, overall spontaneous impromptu hand-drawn draft aesthetic. Loose casual lines of varying thickness, slightly messy but rhythmic and highly expressive, prioritizes playful summarization, exaggeration and casual charm over strict realism or fine detailed rendering. Colors are rough blocked shapes with obvious dry brush texture, retain visible uneven smudge marks, brush strokes, dry flyaway marks and layered coverage, color palette is automatically adapted to fit the tech AI builder theme, fully maintains graffiti sketch summarized color style, strictly no transparent watercolor smudging, no soft watercolor gradients, no paper texture, no soft blurring, no dreamy hazy effects. Background is mostly blank plain white, keeps simple, relaxed unfinished design feel, can add a tiny amount of auxiliary doodle elements including small arrows, quick marks, circled lines, short casual handwritten text to enhance sketchbook casual aesthetic, no overcrowded elements that distract from the main subject. The AI builder character, pose, relevant tech-themed accessory elements and simplified surrounding details are creatively generated to fit the theme, all consistent with the unified graffiti sketch exaggerated summarized style, no complex realistic backgrounds, no excessive unnecessary details. Add a subtle small high-end refined signature "LumenMark" naturally placed in the bottom left or bottom right corner as artwork sign-off, style matches the overall layout perfectly, does not disrupt the main subject composition, no overly large size, no abrupt or cheap appearance.